Mobile communication devices, such as mobile telephone handsets, include alerting mechanisms to alert the user to certain events, such as an incoming communication or some type of alarm related to an application running on the device. Conventional alerting mechanisms include a ring tone, which is often customizable. In fact, portions of songs or other types of audio files can be used as ring tone replacements in many conventional devices. Many conventional devices also include a motor that can be configured to vibrate to indicate an alert, in order to provide a silent mode of operation.
Many mobile communication devices also include light sources, such as light emitting diodes (LEDs). LEDs can be used to backlight a liquid crystal display on the mobile communication device and to light a keyboard on the device. The LEDs can, for example, be lit when a communication is received, for example, a mobile telephone call. The LEDs can also be lit when a key or keys are depressed.
One or more LED's can be used depending on the requirements of a particular embodiment. Moreover, light pipes can be used in conjunction with the LEDs. A light pipe is a type of wave guide that can be used to guide the light being emitted from one or more LEDs from the light emitting surface of the LED to the point were the light is to be delivered. A light pipe can also be used to evenly defuse the light being delivered over a broad area, or to focus the light on a specific point. For example, where it once took several LEDs arrayed along the sides of a mobile communication device display to provide sufficient backlighting behind the entire display, a single LED can now often be used when combined with a light pipe that is flat and roughly the same dimension as the display. The light pipe has a narrow opening at the surface of the LED and then becomes broad and fiat. The broad flat section fits behind the display and diffuses the light being emitted from the LED throughout the entire flat section, thus backlighting the entire display.
Light pipes can come in many shapes and dimensions, for example a light pipe can be used to form a border around a mobile communication device display. Thus, for example, one LED and one light pipe can be used to backlight a mobile communication device display, while another light pipe can be used as a border for the display. A second LED, e.g., of a different color can then be used in conjunction with this second light pipe to light up the border around the display.
Light pipes provide flexibility to the designer of a mobile communication device in that LEDs or other light sources can be placed where convenient and the light can be “piped” to the delivery point. In other words, the LED or light source placement is not constrained by any need to place it next to the point of delivery. The ability to conveniently place the LED or light source can allow more efficient placement of the LED or light source.